 Simulations show that image quality in Positron Emission Tomography can be improved by exploiting the polarization entanglement of 511 keV photons [1]}. These entangled states were also used in Compton scattering experiments [2]}, [3]} to test the kind of entanglement discussed by Einstein, Podolsky and Rosen [4]}, [5]}, [6]}. However, these experiments had to assume theory can predict the angular distributions to a similar accuracy as for non-entangled photons [7]}. To this day, this assumption must be invoked because the question concerning the accuracy of Compton scattering theory in the presence of entanglement still remains open [8]}, [9]}.
